Cooling system



June 1, 1943.

F. E. ROWAN COOLING SYSTEM Filed Feb. 10, 1941 INVENTOR, R0 W/'\ /V ATTORNEY.

Patented June 1, 1943 COOLING SYSTEM Frank E. Rowan, Kenosha, Wis., assignor to Nash- Kelvinator Corporation, Kenosha, Wis., a corporation of Maryland Application February 10, 1941, Serial No. 378,202

12 Claims.

This invention relates to cooling systems and has particular reference to the cooling system of an internal combustion motor.

Present day automobile motors are provided with a cooling jacket through which a cooling medium such as water is circulated by means of a pump. The water is passed through a radiator which is subjected to a blast of air for removing heat from the water. Present day radiators are vented directly to the atmosphere to provide for the expansion of the water due to entrained air and steam caused by the heating of the water. The vent is provided at the top of the radiator, usually in or around the filler cap. These systems are subject to the disadvantage that the repeated expansion and contraction in the volume of water causes a great deal of water to be forced out through the vent, thus reducing the supply of water in the system. When relatively expensive antifreeze solution is added to the water, this loss of cooling medium becomes expensive and is desirable to be avoided. Present day cooling systems also provide only a hydrostatic pressure head at the top of the radiator core to return the water to the circulating pump, which, during high speed operation of the motor, may not be sufiicient to supply the pump with the result that a high suction is developed around the pump, causing air to leak into the system along the pump shaft and hose connection. The air thus entrained in the water causes further expansion in the volume of water andfurther loss through the radiator vent. The efficiency of the pump is also .vide a cooling system in which vaporized antifreeze solution will be condensed before the vapor has a chance to escape through the vent in the system.

It is another object of this invention to reduce the amount of air leaking into the cooling system.

It is another object of this invention to provide an overflow tank which will retain the ex- --panded amount of cooling medium and return it to the cooling system as the cooling medium contracts.

Other objects and advantages of this invention will be apparent from a consideration of the following description and claims and the attached drawings, of which there isone sheet, and in which- Figure 1 represents a diagrammatic view of an internal combustion motor with its associated radiator and cooling system; and

Figure 2 represents a sectional View taken along a plane indicated by the line 2-2 in Figure 1 and looking in the direction of the arrows.

The motor I0 is provided with the usual type of cooling jacket through which a cooling medium is circulated by the pump l2. The pump I2 is driven from the generator shaft [4 which is in turn operated by the belt It. The belt I6 is operated from the pulley l8 positioned on the front end of the crank shaft 20. The belt (6 also serves to operate a fan 22 for drawing air through the radiator core 24 of a radiator generally indicated at 26. The particular arrangement for driving the pump does not form a part ofthis invention and so is not described more fully.

Cooling medium is supplied to the pump l2 through a return pipe 28 and is forced out of the motor through a discharge pipe 30. The discharge pipe 30 is connected to an upper header 32 on the top of the radiator core 24, and the return pipe 28 is connected to the underside of a lower header 34 positioned at the bottom of the core 24.

The upper header 32 isprovided with a filler spout 36 which is arranged to be closed by an air tight cap 38. This particular location of the filler spout is not material to the invention as will appear later. The lower header 34 is provided with a baffle 40 which extends completely across the width of the header 34 between the lower end of the core 24 and the outlet 4| from the header to the return pipe 28. Cooling medium entering the lower header 34 from the core 24 is forced to pass over the lip 42 at the rear edge of the baflle 40 and a trap 44 is provided along the upper surface of the lower header 34 just over the lip 42.

The trap 44 is formed by the sloping top walls 45 of the header 34 which are joined together near the center of the header. The trap 44 is connected to an overflow tank 4% positioned on top of the upper header 32 by means of a vent pipe 48 connected to the sloping walls 45 at their --ingpumped into the tank.

ential -ofpressure existing at the pump-Will be older systems.

junction. All of the above connections are made as air tight as possible. The overflow tank 46 is provided with a vent 50 which communicates between the overflow tank and the atmosphere surrounding the motor and radiator. If desired, the vent 59 may take the form of a filler spout if a scalable vent is provided in the upper header 32 to permit air to escape when the system is filled with the cooling medium.

In operation, the cooling system will be filled with a cooling medium such as water to the level of the top of the filler spout 35. This level corresponds to the level in the overflow tank indicated by the dotted line 52. The filler spoutis then sealed by the air tight cap381 so that there is a closed body of water from the motor [0 through the discharge pipe 30, upper header 32, core 24, lower header 3%, return pipe 28 and pump l2. As the pump [2 is operated, water on the pressure side of the pump will be forced directly through the cooling system to the suction side of the pump. The hydrostatic head of Water-standing in the vent piped-Sand overflow tank 45 to the level indicated at 52 will prevent. water from be- The only differthat sufficient to overcome the friction losses of the cooling medium in passing through the system, thusvery little airwill leak into the system around the pump [2 along the shaft iii-and the hose connections.

As the" cooling. medium passes from. the relatively constricted core 2 i to the broad passage over the baffle 82, .it is slowed up in passing under the trap 44 .due tov the. increased area. through which. it has toiflow. .Anyair which: has been entrained in the coolingmediurn will have ample opportunity .to rise. as bubbles into the trapAQ .from where .it will rise. through the pipe {8 to thevented overflowtanksti. Entrainedair is thus purged. from the cooling. system.

'Should the. volumeof the cooling medium expand, the excess. volume will be forced up the ,pipe

18 to the .overflow tank t which. has capacity forretaining theincreased volume of cooling medium. The size of the overflow tank may, easily be-. determined to provide sumcient capacityover the level ,zby considering the volumeof cooling .medium in the system and the.co-efiicie nt of eX- pansion: and temperature range ;of the medium.

Attention is called tothe fact that since the system,will take in less-,air than the older type of cooling system and sincemost of the entrained air will be exhausted through ,thepipe-M, the

present cooling system will not besubject to as much expansion .of the cooling mediumas in the The-pump i2 will also operate more efficiently due to the lack of air in the system. Upon contraction of the volume of ,the cooling medium, that portion of the coolingmedium stored in the tank 36 abovethe level iiz will return through the: pipe 48 to the lower header 34. Since the only place for air to return to the cooling system with the contracting cooling medium is through the-vent 5B and pipe 43 it should be evident that no. air will enter the cooling system until the level of thecooling-medium-has fallen sufficiently to create a vacuumin the system which is strong enough to draw air through the column of water in the pipeas; The cooling system thus preventsair from entering the system through theventandbyleakage around the pumpand thus reduces the amountof expansion ;of;the, body of the cooling medium.

\ stantly open ventas a safety factor. .is operablewith cross flow radiators as well as When the cooling system is filled with antifreeze solution, which generally has a lower boiling point than water, any vapors caused by boiling of the anti-freeze solution will be forced first through the sealed upper header 32 and core 24 where they will be at least partially condensed by the cooling action of the air stream passing through the core before they are passed underneath the trap 44. Since the trap 44 forms the only passage for the escape of vapors from the system, the loss of anti-freeze solution due to boiling of the solution is materially decreased.

jThe system provides all of the advantages of a sealed cooling system while retaining a con- The system with the conventional vertical flow radiator illustrated. The more or less diagrammatic disclosure of the system is to be taken as an example only and not as a limitation of my invention, to which I make the following claims.

: I claim:

1. A cooling system for an internal combustion motor comprising a closedcirculating system, a radiator in said system, alower header for-said radiator having an inlet and outlet,- a baffle-in said header positioned: between-said inletand outlet, a trap positioned over. saidbafile, and a vent pipeopening into said trap and extending to apoint above said cooling system, said baflie being arranged to reduce the speed of the'cooling me- .dium circulating in saidsystem as themedium passes underneath. said trap.

3. A cooling system for'an internal combustion motor comprising a closed circulating system,- a

radiator-in saidsystem a lowerheader for said radiator having an .inlet and-outlet, an-overflow tank positioned. above said circulating system,

and a.ventpipe-communicating between said -:lower headerand said overflow tank, said'overflow tank being vented to the atmosphere.

4. A cooling system'for an:internal combustion .motor .comprising aclosed circulating system, meanszforming. a relatively constricted passage at a lower portion of said circulating system, means forming a relatively broadpassage adjacent to said constricted passage, .a trap-positioned over said broadpassagaand a vent pipe communicating between said trap and the atmosphere surrounding said a circulating system at a point above the levelof said circulating system, said circulating;systembeingarranged to pass a cooling medium first through said-constricted passage and then. throughsaid broad passage.

. 5. A cooling. system foran'internal: combustion ,motor comprising a .sealed upper header, a

core connectedto. :the. underside of said .upper header, a lower header connected to the bottom of said core and having a top wall unobstructed by said core,,said top wall .slopinguupwardly to the center of said lowerheader tozformav trap,. a baflle positioned in said lower header underneath tank positioned on top of said upper header, and a vent pipe communicating between said trap and said overflow tank.

6. A cooling system for an internal combustion motor comprising a sealed upper header, a core connected to the underside of said upper header, a lower header connected to the bottom of said core, said top wall sloping upwardly to the center of said lower header to form a trap, a bafile positioned in said lower header underneath said core and having a lip positioned underneath said trap, an outlet for said lower header positioned underneath said baflle, an overflow tank positioned on top of said upper header, a Vent pipe communicating between said trap and said overflow tank, and means forming a closable opening for filling said system with a cooling medium.

7. A cooling system for an internal combustion motor comprising a pair of headers, a core extending between said headers, a pipe for delivering a coolant from said motor to the upper of said headers, a second pipe for delivering coolant from the other of said headers to said motor, an overflow tank positioned above said upper header, a vent pipe connected between a point near the lower level of said system and said overflow tank, said overflow tank defining a constantly open aperture communicating with the atmosphere about said system and a pump for circulating coolant in said system.

8. A cooling system for an internal combustion motor comprising a pair of closed headers, a core extending between said headers, a pipe for delivering a coolant from said motor to the top of one of said headers, a second pipe for delivering coolant from the bottom of the other of said headers to said motor, an overflow tank positioned above said first pipe, means forming a trap in said system between said core and said other pipe, a vent pipe connected between said trap and said overflow tank, and a pump for circulating coolant through said system.

9. A cooling system for an internal combustion motor comprising a pair of headers, a core extending between said headers, a pipe for delivering a coolant from said motor to the top of one of said headers, a, second pipe for delivering coolant from the bottom of the other of said headers to said motor, means in said other header defining a passage of enlarged area through which the coolant must flow, a vent pipe communicating with said other header above said means, an overflow tank positioned above said first pipe, said tank being vented to the atmosphere around said system and connected to said vent pipe, and a pump for circulating coolant in said system.

10. A cooling system for an internal combustion motor comprising a pair of headers, a core extending between said headers, a sealable filling spout connected to the top of one of said headers, a pipe for delivering a coolant from the motor to the top of one of said headers, a second pipe for delivering coolant from the bottom of the other of said headers to said motor, a baflle positioned in said other of said headers between said core and said second pipe, an overflow tank positioned above said first pipe, a vent pipe communicating between said overflow tank and said other header at a point just above said baffle, and a pump for circulating coolant through said system.

11. A cooling system for an internal combustion motor comprising a cooling jacket, a radiator, a fluid impeller, means connecting said jacket, radiator and impeller in a closed circuit, sealable means for admitting a cooling fluid at the top of said circuit, an air trap interposed in said circuit at a point below the upper level thereof and over the path of flow of the cooling fluid at that point, and means forming a vent extending from said air trap to a point above the upper level of said circuit.

12. A cooling system for an internal combustion motor comprising a cooling jacket, a radiator, a fluid impeller, means connecting said jacket, radiator and impeller in a closed circuit, sealable means for admitting a cooling fluid at the top of said circuit, an air trap interposed in said circuit at a point below the upper level thereof, and means forming a vent extending from said air trap to a point above the upper level of said circuit, said last mentioned means forming an overflow tank above the upper level of said circuit.

FRANK E. ROWAN. 

